At first glance, you might think that this was an alien blaster. Believe it or not, this is a real design! This model, the JLS Beretta RX-4 STORM is fitted to accept standard M4 magazines. It is very ergonomic and has an adjustable stock.

The
first thing I noticed with the stock extended was that it moved in all
directions and I had to super glue the retainer in the receiver to stop
most of this movement. However even after being glued there was still a
bit of play on the stock.
The safety and selector switches located next to the trigger. The
safety is a bar type similar to a L85 and the selector is pushed up for
auto and down for single shot. Both are pretty solid and shouldn't give
any problems.
The hop can be adjusted by pulling the cocking lever backwards and turning the hop dial. This is similar to a M16/M4 hop up.

The
magazine is released by a button on the right hand side of the gun and
the button on the left hand side is false. I think JLS should have made
the release on the left hand side as it means now that to remove the
magazine you have to use your trigger hand (if you are right handed).To
fit a battery the front fore grip needs to be removed and this is done
by removing the large nut at the front of the fore grip and it slides
off.

The foregrip will only hold a small battery as the room inside it is limited unless you fancy taking a Dremel to it.

The
thread that holds the nut on is held on with super glue so I'm not sure
it will stay there however if it comes loose then all you need to do is
super glue it back in place.

When I chrono'd the RX4, it was firing at 380 FPS and I decided to fit another spring to bring the FPS down to sub 350 FPS.

To get to the gearbox you need to remove the stock, the pistol grip,
front foregrip and then split the receiver in half. There are quite a
few springs and pins etc. That could be lost easily so be careful taking
the AEG apart.

The gearbox is a unique design and has a funky motor mount which can swing up